CVE-2026-39906
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUnisys WebPerfect Image Suite versions 3.0.3960.22810 and 3.0.3960.22604 expose a deprecated .NET Remoting TCP channel that allows remote unauthenticated attackers to leak NTLMv2 machine-account hashes by supplying a Windows UNC path as a target file argument through object-unmarshalling techniques. Attackers can capture the leaked NTLMv2 hash and relay it to other hosts to achieve privilege escalation or lateral movement depending on network configuration and patch level.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceUnisys WebPerfect Image Suite versions 3.0.3960.22810 and 3.0.3960.22604 expose a deprecated .NET Remoting TCP channel that accepts Windows UNC paths as object arguments. Unauthenticated remote attackers can trigger object-unmarshalling with a UNC path, causing the server to authenticate to the attacker-controlled SMB share and leak the NTLMv2 machine-account hash. The captured hash can be relayed to achieve privilege escalation or lateral movement.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 3.0.3960.22604= 3.0.3960.22810CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify if Unisys WebPerfect Image Suite is installedCheck the Windows registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall for an entry named 'Unisys WebPerfect Image Suite' or look in Add/Remove Programs. Also check common installation paths like C:\Program Files\Unisys\WebPerfect Image Suite\Affected if The software is present on the system
-
Verify the installed version numberLocate the version information in the registry key mentioned above, or check the file properties of the main executable (typically named WebPerfect.exe or similar in the installation directory)Affected if The version is exactly 3.0.3960.22604 or exactly 3.0.3960.22810
-
Check if .NET Remoting TCP channel service is runningOpen Windows Services console (services.msc) and look for a service related to WebPerfect Image Suite that exposes a .NET Remoting endpoint. Also use netstat -ano to check for listening TCP ports (common .NET Remoting ports include 808, 843, or custom configured ports)Affected if The WebPerfect service is running and listening on TCP ports accessible from the network
-
Verify the exposed endpoint accepts UNC path parametersReview application configuration files (often named WebPerfect.exe.config or app.config in the installation directory) to confirm .NET Remoting is configured with a TCP channel that accepts object parametersAffected if A TCP remoting channel is configured and exposed without authentication
The system is affected if Unisys WebPerfect Image Suite version 3.0.3960.22604 or 3.0.3960.22810 is installed with the .NET Remoting TCP channel enabled and accessible on the network.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataDisable the deprecated .NET Remoting TCP channel in the application configuration, implement network segmentation to restrict SMB access, and apply vendor patches when available. Consider disabling NTLM authentication or enforcing SMB signing to prevent relay attacks.
- Consultation8.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $15,616.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-39906 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-39906 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data